Poster: Mineral nutrition

Abs # 198: Calcium availability in the pads of the prickly pear cactus

Presenter:	McConn, Michele M., mmcconn@bcm.tmc.edu
Authors	Nakata, Paul A. (A)   McConn, Michele M. (A)
Affiliations:	(A): USDA/ARS Children's Nutrition Research Center

The pads (nopales) of the prickly pear cactus are considered a good source of minerals and other nutrients based on compositional analysis. In this study, we take this analysis a step further by assessing the availability of selected minerals in nopales using an in vitro digestion and dialysis method. The results obtained suggest that although nopales is enriched in a number of minerals, its tissue calcium is not freely available. Microscopic analysis, energy dispersive x-ray microanalysis, and oxalate measurements suggest that this reduction in available calcium is a result of its sequestration in the form of calcium oxalate crystals. The issue of mineral availability in plant foods is important when considering the dependence of many populations around the world on plant foods as their main source of minerals and other nutrients.